Recent Insights into Plant miRNA Biogenesis: Multiple Layers of miRNA Level Regulation
Mateusz Bajczyk,
Artur Jarmolowski,
Monika Jozwiak,
Andrzej Pacak,
Halina Pietrykowska,
Izabela Sierocka,
Aleksandra Swida-Barteczka,
Lukasz Szewc,
Zofia Szweykowska-Kulinska
Affiliations
Mateusz Bajczyk
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
Artur Jarmolowski
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
Monika Jozwiak
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
Andrzej Pacak
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
Halina Pietrykowska
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
Izabela Sierocka
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
Aleksandra Swida-Barteczka
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
Lukasz Szewc
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
Zofia Szweykowska-Kulinska
Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Uniwersytetu Poznanskiego 6, 61-614 Poznań, Poland
MicroRNAs are small RNAs, 20–22 nt long, the main role of which is to downregulate gene expression at the level of mRNAs. MiRNAs are fundamental regulators of plant growth and development in response to internal signals as well as in response to abiotic and biotic factors. Therefore, the deficiency or excess of individual miRNAs is detrimental to particular aspects of a plant’s life. In consequence, the miRNA levels must be appropriately adjusted. To obtain proper expression of each miRNA, their biogenesis is controlled at multiple regulatory layers. Here, we addressed processes discovered to influence miRNA steady-state levels, such as MIR transcription, co-transcriptional pri-miRNA processing (including splicing, polyadenylation, microprocessor assembly and activity) and miRNA-encoded peptides synthesis. MiRNA stability, RISC formation and miRNA export out of the nucleus and out of the plant cell also define the levels of miRNAs in various plant tissues. Moreover, we show the evolutionary conservation of miRNA biogenesis core proteins across the plant kingdom.
